One of the major reasons we've never had one is the fact that it's really hard to moderate. As it is, VMs are a little difficult and we don't know about most problems until they get reported. But at least they can be reported and deleted. With a shout box, we don't have much control over what gets put in there, and it would all be happening so fast that the staff would have to read through hundreds of little messages to make sure everyone was sticking to forum rules.